<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Ldap
 * @subpackage Ldif
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Encoder.php 17829 2009-08-26 15:07:10Z sgehrig $
 */

/**
 * Zend_Ldap_Ldif_Encoder provides methods to encode and decode LDAP data into/from LDIF.
 *
 * @category   Zend
 * @package    Zend_Ldap
 * @subpackage Ldif
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Ldap_Ldif_Encoder
{
	/**
	 * Additional options used during encoding
	 *
	 * @var array
	 */
	protected $_options = array(
        'sort'    => true,
        'version' => 1,
        'wrap'    => 78
	);

	/**
	 * @var boolean
	 */
	protected $_versionWritten = false;

	/**
	 * Constructor.
	 *
	 * @param  array $options Additional options used during encoding
	 * @return void
	 */
	protected function __construct(array $options = array())
	{
		$this->_options = array_merge($this->_options, $options);
	}

	/**
	 * Decodes the string $string into an array of LDIF items
	 *
	 * @param  string $string
	 * @return array
	 */
	public static function decode($string)
	{
		$encoder = new self(array());
		return $encoder->_decode($string);
	}

	/**
	 * Decodes the string $string into an array of LDIF items
	 *
	 * @param  string $string
	 * @return array
	 */
	protected function _decode($string)
	{
		$items = array();
		$item = array();
		$last = null;
		foreach (explode("\n", $string) as $line) {
			$line = rtrim($line, "\x09\x0A\x0D\x00\x0B");
			$matches = array();
			if (substr($line, 0, 1) === ' ' && $last !== null) {
				$last[2] .= substr($line, 1);
			} else if (substr($line, 0, 1) === '#') {
				continue;
			} else if (preg_match('/^([a-z0-9;-]+)(:[:<]?\s*)([^:<]*)$/i', $line, $matches)) {
				$name = strtolower($matches[1]);
				$type = trim($matches[2]);
				$value = $matches[3];
				if ($last !== null) {
					$this->_pushAttribute($last, $item);
				}
				if ($name === 'version') {
					continue;
				} else if (count($item) > 0 && $name === 'dn') {
					$items[] = $item;
					$item = array();
					$last = null;
				}
				$last = array($name, $type, $value);
			} else if (trim($line) === '') {
				continue;
			}
		}
		if ($last !== null) {
			$this->_pushAttribute($last, $item);
		}
		$items[] = $item;
		return (count($items)>1) ? $items : $items[0];
	}

	/**
	 * Pushes a decoded attribute to the stack
	 *
	 * @param array $attribute
	 * @param array $entry
	 */
	protected function _pushAttribute(array $attribute, array &$entry)
	{
		$name = $attribute[0];
		$type = $attribute[1];
		$value = $attribute[2];
		if ($type === '::') {
			$value = base64_decode($value);
		}
		if ($name === 'dn') {
			$entry[$name] = $value;
		} else if (isset($entry[$name]) && $value !== '') {
			$entry[$name][] = $value;
		} else {
			$entry[$name] = ($value !== '') ? array($value) : array();
		}
	}

	/**
	 * Encode $value into a LDIF representation
	 *
	 * @param  mixed $value   The value to be encoded
	 * @param  array $options Additional options used during encoding
	 * @return string The encoded value
	 */
	public static function encode($value, array $options = array())
	{
		$encoder = new self($options);
		return $encoder->_encode($value);
	}

	/**
	 * Recursive driver which determines the type of value to be encoded
	 * and then dispatches to the appropriate method.
	 *
	 * @param  mixed $value The value to be encoded
	 * @return string Encoded value
	 */
	protected function _encode($value)
	{
		if (is_scalar($value)) {
			return $this->_encodeString($value);
		} else if (is_array($value)) {
			return $this->_encodeAttributes($value);
		} else if ($value instanceof Zend_Ldap_Node) {
			return $value->toLdif($this->_options);
		}
		return null;
	}

	/**
	 * Encodes $string according to RFC2849
	 *
	 * @link http://www.faqs.org/rfcs/rfc2849.html
	 *
	 * @param  string $string
	 * @param  boolen $base64
	 * @return string
	 */
	protected function _encodeString($string, &$base64 = null)
	{
		$string = (string)$string;
		if (empty($string)) {
			return '';
		}

		/*
		 * SAFE-INIT-CHAR = %x01-09 / %x0B-0C / %x0E-1F /
		 *                  %x21-39 / %x3B / %x3D-7F
		 *                ; any value <= 127 except NUL, LF, CR,
		 *                ; SPACE, colon (":", ASCII 58 decimal)
		 *                ; and less-than ("<" , ASCII 60 decimal)
		 *
		 */
		$unsafe_init_char = array(0, 10, 13, 32, 58, 60);
		/*
		 * SAFE-CHAR      = %x01-09 / %x0B-0C / %x0E-7F
		 *                ; any value <= 127 decimal except NUL, LF,
		 *                ; and CR
		 */
		$unsafe_char      = array(0, 10, 13);

		$base64 = false;
		for ($i = 0; $i < strlen($string); $i++) {
			$char = ord(substr($string, $i, 1));
			if ($char >= 127) {
				$base64 = true;
				break;
			} else if ($i === 0 && in_array($char, $unsafe_init_char)) {
				$base64 = true;
				break;
			} else if (in_array($char, $unsafe_char)) {
				$base64 = true;
				break;
			}
		}
		// Test for ending space
		if (substr($string, -1) == ' ') {
			$base64 = true;
		}

		if ($base64 === true) {
			$string = base64_encode($string);
		}

		return $string;
	}

	/**
	 * Encodes an attribute with $name and $value according to RFC2849
	 *
	 * @link http://www.faqs.org/rfcs/rfc2849.html
	 *
	 * @param  string       $name
	 * @param  array|string $value
	 * @return string
	 */
	protected function _encodeAttribute($name, $value)
	{
		if (!is_array($value)) {
			$value = array($value);
		}

		$output = '';

		if (count($value) < 1) {
			return $name . ': ';
		}

		foreach ($value as $v) {
			$base64 = null;
			$v = $this->_encodeString($v, $base64);
			$attribute = $name . ':';
			if ($base64 === true) {
				$attribute .= ': ' . $v;
			} else {
				$attribute .= ' ' . $v;
			}
			if (isset($this->_options['wrap']) && strlen($attribute) > $this->_options['wrap']) {
				$attribute = trim(chunk_split($attribute, $this->_options['wrap'], PHP_EOL . ' '));
			}
			$output .= $attribute . PHP_EOL;
		}
		return trim($output, PHP_EOL);
	}

	/**
	 * Encodes a collection of attributes according to RFC2849
	 *
	 * @link http://www.faqs.org/rfcs/rfc2849.html
	 *
	 * @param  array $attributes
	 * @return string
	 */
	protected function _encodeAttributes(array $attributes)
	{
		$string = '';
		$attributes = array_change_key_case($attributes, CASE_LOWER);
		if (!$this->_versionWritten && array_key_exists('dn', $attributes) && isset($this->_options['version'])
		&& array_key_exists('objectclass', $attributes)) {
			$string .= sprintf('version: %d', $this->_options['version']) . PHP_EOL;
			$this->_versionWritten = true;
		}

		if (isset($this->_options['sort']) && $this->_options['sort'] === true) {
			ksort($attributes, SORT_STRING);
			if (array_key_exists('objectclass', $attributes)) {
				$oc = $attributes['objectclass'];
				unset($attributes['objectclass']);
				$attributes = array_merge(array('objectclass' => $oc), $attributes);
			}
			if (array_key_exists('dn', $attributes)) {
				$dn = $attributes['dn'];
				unset($attributes['dn']);
				$attributes = array_merge(array('dn' => $dn), $attributes);
			}
		}
		foreach ($attributes as $key => $value) {
			$string .= $this->_encodeAttribute($key, $value) . PHP_EOL;
		}
		return trim($string, PHP_EOL);
	}
}